Peripheral nerves are often damaged or severed when a person suffers a traumatic injury. Direct nerve repair can be used for small gaps, but larger gaps are sometimes repaired using nerve grafts. While the axonal segment proximal to the site of the injury can regenerate new axonal sprouts, nonfunctional distal axon segments and their myelin sheaths are believed to have growth-inhibitory effects that curtail nerve regeneration. Substantial evidence indicates that the clearance of non-functional nerve elements improves axonal growth in the distal nerve segment.
One technique for improving the effectiveness of nerve grafts includes clearing the nerve graft of nonfunctional nerve elements before surgically installing the graft into the repair site. Nerve grafts, for example, acellular grafts, having a structure and composition similar to a nerve fascicle, can assist in axonal regeneration by providing a scaffold through which new axon segments can grow. An acellular nerve graft, sometimes called a processed nerve graft, supports and directs the growing axon segments with supporting structures, while providing a pathway clear of axonal and myelin debris.